Large Hadron Collider smashes protons at 7-TeV

LONDON  The Large Hadron Collider housed at CERN (Geneva, Switzerland) has been re-opened and two beams of protons have been brought into a collision with an energy of 7 tera electron-volts.

The event happened at 13:06 Central European Summer Time today (March 30). The high-energy collision effectively marks the opening of Europe's LHC research project, which intends to recreate conditions at a time close to the origin of the universe and provide an experimental platform for the most advanced quantum particle physics research.

The 7-TeV energy collision is three and a half times higher than previously achieved at a particle accelerator. The record-breaking achievement goes some way towards overcoming the disappointment that was felt when the LHC broke down soon after it was opened for the first time in September 2008.

After more than a year repairing damage and verifying the demanding engineering the collider has been brought up gradually and two beams of protons have been circling in opposite directions around the underground particle accelerator for many days. Being a cryogenic machine operating at very low temperature, the LHC takes about a month to bring up to room temperature and another month to cool down.

Now that the collider is chilled and running CERN will let it run for between 18 and 24 months with the objective of delivering enough data to a number of experiments to make significant advances across a wide range of physics. As soon as they have used the set up to "re-discover" the known standard model particles, the LHC experiments will start the systematic search for the Higgs boson. The Higgs boson is a particle predicted by the standard model not yet observed. The combined analysis of data from two experiments  Atlas and CMS &@151; will allow experimenters to explore a wide mass range in the hunt for Higgs. If the Higgs boson has a mass near 160-GeV, it could be discovered relatively quickly, CERN said. If the Higgs boson is much lighter or very heavy, it will be harder to find in this first LHC run.

"With these record-shattering collision energies, the LHC experiments are propelled into a vast region to explore, and the hunt begins for dark matter, new forces, new dimensions and the Higgs boson," said Fabiola Gianotti, a spokesperson for ATLAS, the proton collision experiment being hosted on the LHC.

"We'll address soon some of the major puzzles of modern physics like the origin of mass, the grand unification of forces and the presence of abundant dark matter in the universe. I expect very exciting times in front of us," said Guido Tonelli, spokesperson of the CMS experiment (Compact Muon Solenoid).

There are also plans to cause lead ion collisions, which is expected to provide insights into the nature of the strong interaction and the evolution of matter in the early universe.

Following this run, the LHC will shut down for maintenance, and to complete the repairs and consolidation work needed to reach the LHC's design energy of 14-TeV.